Compact snap acting device



' July 12, 1949. O, H, KAMINKY 2,476,045

COMPACT SNAP-ACTING DEVICE Filed Aug. 23, 1946 IN VEV TOR.

ATTORNEYS Patented July 12, 1949 COMPACT SNAP ACTING DEVICE Oscar H.Kaminky, Sycamore, Ill., assignor to First Industrial Corporation,Wilmington, DeL, a corporation of Delaware Application August 23, 1946,Serial No. 692,421

6 Claims.

The present invention relates to improvements in snap acting devices andparticularly to an improved snap acting mechanism especially adapted foruse in a compact precision type electric switch.

An object of this invention is to provide a snap acting mechanism whichwill occupy a minimum of space; which may conveniently be incorporatedwithin a circular casing; and which is operable by a center mountedbutton.

Specifically, one form of my invention contemplates the provision of asnap spring system comprising three apertured spring members, one nestedwithin another, about a common center and so interconnected and somounted on supports, one of which is movable that when the movablesupport is moved the spring system will be moved through an axis ofmaximum stress to move a portion of the spring system throughpreselectedpositions by snap action.

Oother objects and advantages will become apparent from the followingdescription in connection with the drawings in which- I Figure l is asectional side view of an electrical switch incorporating a snap actingdevice in ac cordance with the present invention; in this case it is aself-returning type of switch and Figure 1 shows it in normal position;

Fig. 1a is a top outside view of Figure 1;

Fig. 2 is a view similar to Figure 1 but showing the parts in theirabnormal position with the operating plunger depressed;

Fig. 3 is a sectional view of Figure 1 taken on line 3-3;

Fig. 4 is a sectional view of Fig. 3 taken on line 4-4;

Fig. 5 is a top view of the spring system alone as employed in theswitch illustrated, and

Fig. 6 is an exploded perspective view of certain parts of the switch.

Considering now the drawings in greater detail, the switch has acircular insulating base I of "Textolite" or similar material. Mountedon one side of the base by rivets or screws 2 is an upstanding anchor orsupport 3 having pivot grooves 4 and 5 formed on opposite sides.Diametrically across from the anchor 3 are upper and lower stationarycontact members 6 and I mounted by rivets or screws 8 and 9,respectively. and electrically insulated from one another by an insert l0f fiber or like insulating material.

The spring system generally designated H is best shown in Figs. and 6.In this instance it comprises three concentric circular members I2, l3and I4 joined at I5 and 16 respectively, and

having mounted at 15 the double headed movable contact H. The firstmember I2 is employed as a tension member comprising spaced circularlyextending elements 12a and I2b having formed at one common end an inneredge 18 pivotally engageable with anchor groove 4; the secondorintermediate member I3, which is employed as a compression member,comprises spaced circularly extending elements 13a and I 3b; andtheinternal member l4 which is employed as a tension memberis aperturedat 19 to form an interioredge 20 engageable with the pivot groove 2!formed on the actuating member 22. It will be noted that the supportingedges l8 and 20 of spring system II are in substantial alignment withthe freely movable portion l5; this feature is important in providingfor maximum movement of the spring portion 15 in response to minimummovement of the movable edge 20. The actuating member 22 in this case isU-shaped. having a. long leg 23 with an end knife edge 24 pivoted inanchor groove 5 and a short leg 25 which is engageablewith the plunger26 for operative movement; The actuating member 22 thus comprises amovable support for the spring system H and its movement in the downwarddirection is limited by the rivet or stop 21. as shown in Fig. 2, and inits upward direction by the engagement of plunger flange 2a with thebell-shaped housing or cover 29. the latter being crimped over theoutside of the base i for engagement therewith. The contact I! on thespring system Ii is movable between the upper and lower stationarycontacts 6 and l which act as stops to limit the movement of the freeend l5 oi the spring system between preselected positions definedthereby. When the switch is employed as a double throw switch, one ofthe rivets 2 will be connected, as by soldering, to a common conductingwire (not shown), and the rivets 8 and 3 will be attached exteriorly ofthe base I to separate conducting wires (not shown) to which theabove-mentioned common wire will be alternately connected through thespring system at alternate positions thereof.

In the present instance, the switch shown is made self-returning to theFigure 1 position by placing the anchor groove 4 above its groove 5.Conversely. it may be made self-returning to the Fig. 2 position byplacing the anchor groove 4 below its groove 5; and a third designvariation is possible in that the switch may be adapted to reset type ofoperation where it will stay in either the Figure 1 or Fig. 2 positionby placing grooves thand 5 at substantially the same level on ane or 3.

To operate the switch the plunger 26 is depressed in the direction ofarrow A in Fig. 2 to move the actuator downwardly through an axis ofmaximum stress which occurs at app ly the position where the actuatorgroove 2| is in the same plane as the tension member elements i211 and[2b. This causes the spring system I l to snap the freely movable end l5upward moving contact ll into engagement with the upper stationarycontact 6. When the depressing force on the button or plunger isreleased, the reverse or self-returning action is similar in that theactuator 22 moves upwardly through an axis of maximum stress where theactuator groove 2| is substantially in the plane of the tension memberelements I20: and 12b whence the contact I! is snapped back downwardlyto its normal or Figure 1 position.

It will be obvious that the spring system need not necessarily becircular in shape as shown, although for many applications this will bepreferable in the interest of compactness combined with a loweroperating force.

While a particular form of the present inven tion has been shown it willbe apparent that minor changes therein will readily suggest themselvesto others skilled in the art without departing from the spirit and scopeof the invention. Having thus described the invention, what is claimedas new is:

1. In a snap acting device, a spring system having an axis of maximumstress comprising first, second and third stressed members nestedtogether, said first and second members having an integrallyinterconnected portion, said second and third members having anintegrally interconnected portion in spaced relation with theinterconnected portion of the first and second members, theinterconnected portion between said first and second members beingmovable between preselected positions, means for mounting said first andthird members at positions remote from their respective interconnectedportions to stress said members, and means engageable with one of saidmounting means to move the supported portion of the respective stressedmember through the axis of maximum stress to move the interconnectedportion between the first and second members between its preselectedpositions with a snap action.

2. In a snap acting device the combination of, a base, a snap springmounted to overlie said base and formed from a metal stamping comprisingfirst spaced tension members interconnected at opposite ends, secondspaced tension members spaced from said first spaced tension members andinterconnected at opposite ends and spaced compression members disposedbetween said first and second spaced tension members and interconnectedat opposite ends and interconnected at spaced positions with said firstand second spaced tension members respectively, one of saidinterconnected portions of said first spaced tension membersbeingmovable between preselected positions, a bracket mounted on saidbase to support the other interconnected end of said first spacedtension members, a pivotally mounted lever supporting one of theinterconnected portions of the second spaced tension members, and meansengageable with said lever for moving the interconnected end of thesecond spaced tension members through the axis of maximum stress to movesaid interconnected end of the first spaced tension members between thepreselected positions with a snap action.

3. In a snap acting device, a spring system formed from flat springsheet material comprising an apertured tension member having a firstportion freely movable between preselected positions and having a secondportion in spaced relation to said first portion, means for supportingsaid second portion, an apertured compression member positioned'interiorly of said tension member and rigidly connected to the freelymovable portion thereof, a second apertured tension member positionedinteriorly of said compression member and connected thereto at aposition remote from the latters connection with the first tensionmember, means for supportin the second tension member at a portionremote from its connection with said compression member, and means formoving one of said supported portions of said spring system through anaxis of maximum stress to move said freely movable portion between saidpreselected positions by snap action.

4. In a snap acting device the combination of, a base, opposed stopsmounted on said base, a. bracket mounted on said base in spaced relationwith said stops, a lever pivotally supported on said bracket andoverlying said base intermediate the bracket and the stops and having anend free to move between opposed positions, a first annular membersupported by said free end, a second annular member in spaced relationwith said first member and supported by said bracket at a point spacedon said bracket from a pivot point of said lever and having a portionmovable between said stops, 2, third annular member disposed betweensaid first and second annular members and having portions respectivelyintegrally interconnected therewith at diametrically opposite points,said first, second, and third annular members forming a snap springsystem having an axis of maximum stress, and means engageable with saidlever for moving the interconnected portion between the first and thirdannular members through the plane of said second annular member wherebyto movesaid portion of the second member between the stops With a snapaction.

5. In a snap acting device the combination of, a base, a snap sprinhaving an axis of maximum stress overlying said base comprising a firstarcuate shaped stressed member, a second arouate shaped stressed memberconcentric with said first member and in spaced relation thereto, saidsecond member having a portion movable between preselected positions,and a third arcuate shaped stressed member concentrically interposedbetween said second and third stressed members and integrally connectedtherewith at diametrically opposite points, a bracket rigidly mounted onsaid base for supporting said sec-- ond stressed member, a leverpivotally supported on said bracket having an end supporting. said firststressed member, and means for actuating said lever whereby said firstmember is moved from one side of said second and third members to theother side thereof whereby to move said portion between the preselectedpositions with a snap action.

6. In a snap acting device the combination of, a base, a snap springhavin an axis of maximum stress overlying said base comprising a firstannular stressed member, a second annular stressed member concentricwith said first member and in spaced relation thereto, said secondmember having a portion movable between preselected positions, and athird annular stressed member interposed between said first and secondstressed members and having portions, respectively, integrally connectedtherewith at diametrically opposite points, means for supporting saidsecond stressed member at a point remote from the movable portion, apivotally supported lever having an end supporting said first stressedmember, and means for actuating said lever whereby the interconnectedportion between the first and third annular members is moved through theplane of said second member to move said portion of the second memberbetween the preselected positions with a snap action.

OSCAR H. KAMINKY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

